The inventive concept relates generally to semiconductor devices, and more particularly, to nonvolatile memory devices capable of recording or erasing data using a charge storing layer. The inventive concept also relates to methods of fabricating this type of nonvolatile memory device.
Host electronic systems incorporating semiconductor devices have become increasingly small in size, but are nonetheless required to process (i.e., store, manipulate, retrieve and erase) large amounts of data. Thus, there is a constant demand for increased operating speed, functional flexibility, and greater integration density in contemporary electronic systems that incorporate nonvolatile memory devices. The resulting scarcity of physical space within electronic systems has motivated designers to implement multi-level nonvolatile memory devices as replacements for conventional single-level devices.
Multi-level nonvolatile memory devices are characterized by a plurality of vertically (i.e., a Z-direction oriented) stacked constituent layers. Each individual layer typically comprises a memory cell array and tends to occupy a lateral footprint (i.e., an X/Y cross-section) about the same size as many conventional single-level, nonvolatile memory devices. The arrangement of components within the multi-level nonvolatile memory devices will vary with design and the fabrication techniques used to mechanically stack and electrically connect the components. Unfortunately, as the number of stacked layers in a multi-level nonvolatile memory device increases, the difficulties associated with fabrication and testing also increase and such difficulties drive up overall manufacturing costs.